The present invention is directed to an improved heat sink for clamping to an electrical component and, specifically, to an electronic semiconductor device or package, such as a TO-220. The TO-220 has a housing which contains electrical connections and metallic tabs which project from the housing. In order to dissipate the heat which is generated by such a semiconductor device, a heat sink of heat conductive material such as resilient sheet metal is applied to the semiconductor device. The heat sink is in contact with the semiconductor device for conducting heat from the semiconductor device. The heat sink also has a relatively large radiating surface for dissipation of heat from the heat sink and away from the semiconductor device.
Prior art self clamping heat sinks for semiconductor devices are awkward to apply to the semiconductor device. Many prior art clamping heat sinks require special tools to apply and to remove. As a result, the tabs which project on the semiconductor device are frequently disturbed and damaged and result in damage to the electrical connections within the semiconductor device. Other prior art heat sinks do not require special tools. However, these prior art heat sinks are difficult to apply and do not remain connected to the degree of reliability normally required in the assembling of circuit boards. In many cases, design features which enables a heat sink to be easily applied and removed from a semiconductor device also result in a diminishing of the contact area between the semiconductor device and the heat sink. This reduces the effectiveness of the heat sink to remove heat from the semiconductor device. Another problem associated with prior art heat sinks is the inability of the heat sink to be positioned in a precise manner on a semiconductor device. This can cause problems with the connections of the semiconductor device with other electronic components on a typical circuit board. Precise positioning of any component in the crowded environment of a typical circuit board can sometimes be very critical. Semiconductor devices of each particular type are available in a multiplicity of sizes, each size requiring a heat sink of a matching size. This requires a large inventory of heat sinks to accommodate an ever increasing number of semiconductor devices. The ever increasing size of heat sink inventory makes assembly of circuit boards and inventory control increasingly more difficult. These and other difficulties experienced with the prior art clamping heat sinks have been obviated by the present invention.
It is, therefore, the principal object of the invention to provide a clamping heat sink for an electronic semiconductor device which can be applied easily to the semiconductor device by hand and which remains securely in position.
Another object of the invention is the provision of a clamping heat sink which can accommodate a wide range of sizes for an electronic semiconductor device of a particular type.
Still another object of the invention is the provision of a clamping heat sink which has a large radiating surface area within a relatively small amount of physical space for efficient and effective dissipation of heat from the heat sink,
A further object of the present invention is the provision of a clamping heat sink which is effective for being coupled with an electronic semiconductor device at a predetermined position on the device with a high degree of accuracy,
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.